WO2010143284A1

WO2010143284A1 - Hydraulic lash adjuster for internal combustion engine

Info

Publication number: WO2010143284A1
Application number: PCT/JP2009/060610
Authority: WO
Inventors: 行雄久保田; 章史田中
Original assignee: 日鍛バルブ株式会社
Priority date: 2009-06-10
Filing date: 2009-06-10
Publication date: 2010-12-16
Also published as: JPWO2010143284A1; EP2441928A4; HK1165843A1; CN102449272B; EP2441928A1; KR101305026B1; CN102449272A; US20120042843A1; KR20120022725A; US8490590B2; JP5269199B2; EP2441928B1

Abstract

A hydraulic lash adjuster which can, when an internal combustion engine is being stopped, retain a large amount of hydraulic oil in a reservoir communicating with a high-pressure chamber. A hydraulic lash adjuster is provided with a body (24) open in the upper part thereof, and also with a plunger (26) in sliding contact with the inner peripheral surface of the body (24) to define a high-pressure chamber (29) at the bottom of the plunger (26) and having an upper end functioning as an operating end. The plunger (26) is provided with a reservoir (28) communicating with an external oil path (32) through an oil supply hole (27a) formed in a side wall of the plunger (26) and through an oil supply hole (24b) formed in a side wall of the body (24). A check valve (40A) for opening the oil supply hole (24b) by the pressure of hydraulic oil led from the external oil path (32) to the oil supply path (24b) is formed in an annular communicating path (T) provided between the side wall of the plunger (26) and the side wall of the body (24) and interconnecting the oil supply hole (27a) and the oil supply hole (24b). When the engine is being operated, a recycle action of leak-down oil is performed. When the engine is being stopped, the check valve (40A) closes the oil supply hole (24b), and as a result, the level (H) of the hydraulic oil in the reservoir (28) communicating with the high-pressure chamber (29) does not descend to a level equal to or lower than an opening end of the body (24), which enables a large amount of hydraulic oil to be retained in the reservoir (28).

Description

Hydraulic lash adjuster for internal combustion engines

The present invention relates to a hydraulic lash adjuster for automatically correcting a valve gap in a valve operating apparatus for an internal combustion engine, and in particular, a large amount of hydraulic oil is held in a reservoir communicating with a high pressure chamber when the internal combustion engine is stopped. It relates to a hydraulic lash adjuster that can be used.

In general, a valve mechanism in an internal combustion engine is easily affected by wear and thermal expansion, and the valve gap changes during operation. Therefore, a hydraulic lash adjuster is used to appropriately correct this gap.

As shown in FIG. 19, the conventional hydraulic lash adjuster has a structure in which a lash adjuster body 2 (hereinafter referred to as an adjuster body) is inserted into a mounting hole 30 formed in the cylinder head 10. The body 24 is inserted into the mounting hole 30 and the plunger 26 is assembled in the body 24 so as to be slidable in the vertical direction. In the plunger 26, a reservoir 28 communicating with the oil gallery 32 opened to the mounting hole 30 through

small holes

24b and 27a is formed. The reservoir 28 communicates with the high pressure chamber 29 through the small hole 27b. The high pressure chamber 29 is filled with hydraulic oil supplied from the oil gallery 32.

Reference numerals

14, 16, and 17 denote valve bodies, cams, and rocker arms, which are valve operating mechanism constituent members. When pressure is applied to the hydraulic oil, the check ball 25a in the high pressure chamber 29 closes the small hole 27b, and the plunger 26 in the locked state constitutes the rocking fulcrum of the rocker arm 17. When the cam nose 16 a presses the rocker arm 17, the rocker arm 17 swings and the valve body 14 slides against the return spring 15 and opens. Thereafter, the valve body 14 is closed by the action of the return spring 15 by the rotation of the cam 16. Reference numeral 23 denotes a plunger spring, and the plunger 26 is always held in contact with the rocker arm 17 by the plunger spring 23 and performs a correction operation so that the clearance of the valve system generated due to thermal deformation or the like is zero. It is.

The cylindrical body 6 is accommodated in the reservoir 28, and the inside of the reservoir 28 is defined by an inner chamber 28a that communicates with the high-pressure chamber 29 and an outer chamber 28b that communicates with the small hole 27a that is the oil supply hole. And even if the adjuster body 2 is inclined as shown in the figure, the oil level of the reservoir inner chamber 28a communicating with the high pressure chamber 29 does not drop below the level indicated by reference numeral H1. Therefore, a large amount of hydraulic oil can be held in the reservoir 28, and there is no problem that air is sucked into the high-pressure chamber 29 when the operation of the internal combustion engine is resumed.

That is, when the reservoir inner chamber 28a is not provided, the oil level in the reservoir 28 is lowered to the position indicated by H2 in FIG. 19 at the same height as the oil supply hole 27a when the internal combustion engine is stopped, and the internal combustion engine is restarted. When hydraulic oil is sucked into the high-pressure chamber 29 from the reservoir 28, etc., air above the oil level is simultaneously sucked into the high-pressure chamber 29 together. In particular, when the internal combustion engine stops while the cam nose 16a and the rocker arm 17 are in contact with each other, the plunger 26 is compressed to the most shortened state (bottomed state). When the internal combustion engine is restarted from this state, the sliding stroke between the plunger 26 and the body 24 is maximized, and the amount of hydraulic oil sucked into the high pressure chamber 29 is maximized. However, since the working oil is not supplied from the internal combustion engine side when the internal combustion engine is stopped, it is almost impossible to secure the amount of oil in the reservoir 28, and the high pressure chamber 29 when the internal combustion engine is restarted is almost impossible. Air intake is the most intense. When air is sucked into the high-pressure chamber 29, the rigidity of the hydraulic fluid that should be generated in the high-pressure chamber 29 when the plunger 26 is pressed is extremely reduced (sponge state), and the valve gap is appropriately corrected. Can not be. However, in the structure shown in FIG. 19, since a large amount of oil (oil level H1) is secured in the reservoir inner chamber 28a when the internal combustion engine is stopped, air is not sucked into the high-pressure chamber 29 when the engine is restarted. It is to be done.

JP-A-6-173622

However, in the above-described prior art (Patent Document 1), since the cylindrical body 6 is accommodated in the reservoir 28, the amount of oil in the reservoir 28 when the internal combustion engine is stopped is in the cylindrical body 6 (reservoir inner chamber 28a). Limited to the amount reserved (there will be a small amount).

In the case where the cylindrical body 6 is not accommodated in the reservoir 28, the hydraulic oil in the high-pressure chamber 29 flows through the gap between the plunger 26 and the body 24 and the small hole 27a which is an oil supply hole during operation of the internal combustion engine. Thus, the recycling action of returning to the reservoir 28 communicating with the high-pressure chamber 29 (hereinafter referred to as the recycling action of the leak-down oil) is performed, so that the amount of oil in the reservoir 28 can be secured when the internal combustion engine is stopped. However, in Patent Document 1, since the cylindrical body 6 is housed in the reservoir 28, the leak-down oil is not recycled, and the amount of oil in the reservoir 28 must be reduced when the internal combustion engine is stopped.

That is, in the prior art, a large amount of hydraulic oil cannot be held in the reservoir 28 when the internal combustion engine is stopped, and there is still a problem that air may be sucked into the high pressure chamber 29 when the operation of the internal combustion engine is resumed. .

Therefore, the inventor stops the structure in which the cylindrical body 6 is accommodated in the reservoir 28, and the body in the annular communication path that connects the oil supply hole 27 a provided in the side wall of the plunger 26 and the oil supply hole 24 b provided in the side wall of the body 24. The oil supply hole 24b is pressed against the inner peripheral surface of the side wall of the body 24 at a position corresponding to the oil supply hole 24b on the 24 side, and the oil supply hole 24b is held in a closed state. If a leaf spring-like check valve that opens the oil supply hole 24b is provided only when the hydraulic oil is pressurized, when the internal combustion engine is operated, the pressurized hydraulic oil is supplied from the open oil supply hole 24b. In addition to being guided into the reservoir 28, the recycling operation of the leak down oil is also performed, and when the operation of the internal combustion engine is stopped, the oil supply hole 24b is held in a closed state, and the oil level in the reservoir 28 is maintained. Since it is held at the opening end position of the di 2, a large amount of hydraulic oil can be held in the reservoir 28, and the above problem (inhalation of air into the high-pressure chamber when the internal combustion engine resumes operation) can be solved. .

And, as a result of making a prototype of a lash adjuster loaded with a leaf spring check valve and verifying its effect, it was confirmed that it was effective.

The present invention has been made in view of the above-described problems of the prior art, and provides a hydraulic lash adjuster capable of holding a large amount of hydraulic oil in a reservoir communicating with a high pressure chamber even when the operation of the internal combustion engine is stopped. There is.

In order to achieve the above object, in the hydraulic lash adjuster for an internal combustion engine according to claim 1, a body that is a bottomed cylinder that opens upward, and a high-pressure chamber that slides on the inner peripheral surface of the body and that is slid onto the bottom of the body. And a plunger having an upper end as an operating end, the plunger having a first oil supply hole formed in a side wall of the plunger and a second oil supply hole formed in a side wall of the body. A reservoir that communicates with an external oil supply passage and a valve hole that communicates the reservoir with the high-pressure chamber are provided, and the high-pressure chamber has a check valve that opens and closes the valve hole in accordance with pressure reduction / pressure-up of the high-pressure chamber And a hydraulic lash adjuster for an internal combustion engine in which a pressing spring for biasing the plunger in the extending direction is accommodated,
The first oil supply hole and the second oil supply hole are communicated via an annular communication path provided between a side wall of the plunger and a side wall of the body, and the second oil supply hole in the annular communication path is provided. A check valve that opens and closes the second oil supply hole is provided at a position corresponding to the oil supply hole in conjunction with the pressure of the hydraulic oil introduced from the external oil supply passage to the second oil supply hole. Configured.
(Operation) The hydraulic oil (engine oil) of the lash adjuster is supplied from the external oil supply passage (oil gallery which is an oil supply passage provided in the cylinder head) to the second oil supply hole and the side wall of the body during operation of the internal combustion engine. It is comprised so that it may be guide | induced to the reservoir | reserver in a plunger through the annular | circular shaped communicating path between the side walls of a plunger, and the 1st oil supply hole. That is, the body and the plunger can move relative to the lash adjuster mounting hole in the circumferential direction, but even if the body and the plunger move (rotate) in the circumferential direction without permission, the first oil supply hole and the second oil supply hole The communication hole is maintained in a communication state via an annular communication path between the side wall of the body and the side wall of the plunger.

At the position corresponding to the second oil supply hole in the annular communication path, the second oil supply hole is opened and closed in conjunction with the pressurizing force of the hydraulic oil guided from the external oil supply passage to the second oil supply hole. When the operation of the internal combustion engine is stopped, the hydraulic oil pressure does not act on the check valve via the second oil supply hole (the pressure of the hydraulic oil acting on the check valve is low). Therefore, the check valve keeps the second oil supply hole closed to prevent the hydraulic oil from passing into the cylinder.

On the other hand, during operation of the internal combustion engine, the pressure of the hydraulic oil acts on the check valve via the second oil supply hole (the pressure of the hydraulic oil acting on the check valve is high). 2 oil holes are opened to allow the passage of pressurized hydraulic oil into the cylinder. In addition, between the high-pressure chamber and the reservoir that are closed by the check valve, the hydraulic oil in the high-pressure chamber also recycles the leak-down oil that returns to the reservoir through the gap between the body and the plunger and the first oil supply hole. It is.

When the operation of the internal combustion engine is stopped, as described above, the second oil supply hole is held closed by the check valve, so that the oil level of the reservoir communicating with the high pressure chamber is set at the open end of the body. Compared to the conventional structure, a large amount of hydraulic oil is retained in the reservoir.

In a hydraulic lash adjuster for an internal combustion engine according to a second aspect, in the hydraulic lash adjuster for an internal combustion engine according to the first aspect, the annular communication path is formed by a lateral groove provided around the inner peripheral surface of the side wall of the body. The check valve is constituted by a belt-like leaf spring that is self-held so as to be in pressure contact with the bottom surface of the lateral groove, and the leaf spring is engaged with the second oil supply hole. Engagement convex portions that are positioned at predetermined positions in the circumferential direction and the axial direction are provided.
(Operation) During the operation of the internal combustion engine, the pressurized hydraulic fluid guided from the external oil supply passage to the second oil supply hole causes the engagement protrusion front surface of the leaf spring engaged with the second oil supply hole to By pressing in a direction deviating from the oil supply hole, the peripheral edge region of the engagement convex portion of the leaf spring is elastically deformed radially inward. For this reason, when the internal combustion engine is stopped, the engagement convex portion peripheral region of the leaf spring that is in close contact with the outer peripheral surface of the annular communication passage (the second oil supply hole peripheral portion of the body inner peripheral surface) is the second oil supply hole peripheral portion. The pressurized hydraulic fluid flows into the annular communication path from the gap formed between the leaf spring and the peripheral portion of the second oil supply hole. When the operation of the internal combustion engine is stopped, the pressing force to the engaging convex portion peripheral region of the leaf spring by the hydraulic oil disappears, and the engaging convex peripheral region is engaged with the second oil supply hole by the elastic force of the leaf spring. Returning to the original position, the peripheral edge region of the engagement convex portion of the leaf spring is closed to the second oil supply hole.

The engagement convex portion provided on the leaf spring is configured, for example, in a spherical shape or a tapered cylindrical shape (conical truncated cone shape) having an outer diameter aligned with the second oil supply hole on the base end side. As the part peripheral region is separated from the second oil supply hole peripheral part, the opening area of the second oil supply hole (the cross-sectional area of the hydraulic oil flow passage) is increased.
Also, the flexibility (spring coefficient) of the leaf spring and the protruding length of the engaging projection are set appropriately, and when the second oil supply hole of the check valve is opened (the engaging projection peripheral edge region of the leaf spring is the body When the inner peripheral surface is separated from the peripheral portion of the second oil supply hole), the distal end portion of the engaging convex portion is configured not to fall off from the second oil supply hole. That is, the engaging convex portion that engages with the second oil supply hole constitutes a positioning means that positions the leaf spring constituting the check valve in the circumferential direction and the axial direction with respect to the second oil supply hole.

In addition, the lateral groove, which is an annular communication path provided around the inner peripheral surface of the side wall of the body, ensures communication between the first oil supply hole and the second oil supply hole, and allows hydraulic oil to flow from the second oil supply hole. In addition to functioning as an oil passage leading to the first oil supply hole, it also functions as positioning means for restricting movement of the leaf spring in the axial direction by contacting the side edge of the leaf spring.

In a hydraulic lash adjuster for an internal combustion engine according to a third aspect, in the hydraulic lash adjuster for an internal combustion engine according to the second aspect, the second oil supply holes are provided at a plurality of substantially equal positions in the circumferential direction of the side wall of the body. The leaf spring is configured to be provided with the engaging projections that respectively engage with the plurality of second oil supply holes.
(Operation) When the internal combustion engine is operated, the pressurized hydraulic oil is guided into the annular communication passage from each of the plurality of second oil supply holes, and therefore, the inflow of the pressurized hydraulic oil into the annular communication passage is much. Smooth.

In addition, the engagement convex portions of the leaf springs respectively engaged with the second oil supply holes provided at a plurality of substantially equal positions in the circumferential direction of the body ensure the leaf springs in the circumferential direction and the axial direction with respect to the second oil supply holes. Position to.

The hydraulic lash adjuster for an internal combustion engine according to claim 4 is the hydraulic lash adjuster for an internal combustion engine according to claim 2 or 3, wherein the leaf spring is provided with a slit, and the engagement convex portion peripheral region of the leaf spring is provided. The flexibility (spring coefficient) was adjusted.
(Operation) When a slit is provided in the leaf spring, the sectional modulus of the region provided with the slit is lower than the sectional modulus of the region provided with no slit, and the flexibility (spring coefficient) in the region provided with the slit is increased. .

Therefore, when a slit is provided in the entire leaf spring, the flexibility (spring coefficient) of the entire leaf spring, that is, the flexibility (spring coefficient) of the peripheral region of the plurality of engaging protrusions is similarly increased. The sensitivity of the check valve (the opening / closing speed of the second oil supply hole by the check valve) increases.

In addition, when a slit is provided only in a part of the leaf spring, the peripheral edge region of one engagement convex portion in which the slit is provided and the flexibility (spring coefficient) is increased is guided to the second oil supply hole. Other engagement convex peripheral areas where the slits are not provided and the flexibility is low, while functioning as a check valve that opens and closes the second oil supply hole by elastically deforming according to the applied pressure of the hydraulic oil Even when the pressurized hydraulic fluid is guided to the second oil supply hole, the second oil supply hole is held closed without elastic deformation. In other words, the peripheral edge of the engaging convex portion in the region where the slit is not provided (the low flexibility region) is always held in close contact with the peripheral portion of the second oil supply hole regardless of whether the internal combustion engine is operating or stopped. Is done. That is, the peripheral edge portion of the engaging convex portion in the region where the slit is not provided (the region where flexibility is low) does not function as a check valve for opening and closing the second oil supply hole, but the leaf spring is opposed to the second oil supply hole. It functions as positioning means for reliably positioning in the circumferential direction and the axial direction.

In the hydraulic lash adjuster for an internal combustion engine according to claim 5, in the hydraulic lash adjuster for an internal combustion engine according to claim 1, the annular communication path is configured by a lateral groove provided around the outer peripheral surface of the side wall of the plunger. The check valve is configured by a sphere having a specific gravity greater than that of the hydraulic oil, the spherical valve having a specific gravity larger than that of the hydraulic oil, which is movable along the lateral groove, and a part of an outer peripheral surface thereof is engaged with the second oil supply hole A longitudinal groove extending upward from the second oil supply hole and allowing the sphere to move in the vertical direction is provided on an inner peripheral surface, and the sphere is circumferentially and axially disposed with respect to the second oil supply hole. It was configured so that it could be positioned.
(Operation) The check valve is composed of a sphere having a specific gravity larger than that of the hydraulic oil, and the configuration thereof is very simple.

During operation of the internal combustion engine, the pressurized hydraulic oil introduced from the external oil supply passage to the second oil supply hole presses the sphere engaged with the second oil supply hole in a direction deviating from the oil supply hole. Then, it rolls (moves) upward along a vertically extending longitudinal groove provided on the inner peripheral surface of the side wall of the body to open a second oil supply hole, and the second oil supply hole is opened. Pressure hydraulic oil flows into the annular communication path. On the other hand, when the operation of the internal combustion engine is stopped, the upward pressing force acting on the sphere due to the hydraulic oil disappears, and the sphere is lowered along the vertical groove by its own weight (the axial positioning means of the sphere as a check valve). To a position where a part of the sphere is engaged with the second oil supply hole and the sphere closes the second oil supply hole. That is, a vertical groove provided on the inner peripheral surface of the side wall of the body that extends upward from the second oil supply hole and allows the sphere to move in the vertical direction is used as a second oil supply hole. The positioning means for positioning in the circumferential direction is configured.

According to the first aspect, when the internal combustion engine is operated, the leakage down oil is recycled. When the internal combustion engine is stopped, the oil level of the reservoir communicating with the high pressure chamber is equal to or lower than the opening end portion level of the body. Therefore, a large amount of hydraulic oil can be held in the reservoir communicating with the high-pressure chamber, and there is no problem that air is sucked into the high-pressure chamber when the operation of the internal combustion engine is resumed.

According to the second aspect, since the leaf spring as the check valve is positioned in the circumferential direction and the axial direction with respect to the second oil supply hole, proper opening / closing operation of the second oil supply hole by the check valve over a long period of time is performed. Guaranteed.

According to the third aspect, since the pressurized hydraulic oil is guided into the annular communication path from each of the plurality of second oil supply holes, the pressurized hydraulic oil from the second oil supply hole into the annular communication path. Smooth inflow can be secured.

In addition, since the leaf spring, which is a check valve, is positioned in the circumferential direction and the axial direction at a plurality of substantially equal parts in the circumferential direction of the body, it is ensured that the check valve can properly open and close the second oil supply hole over a long period of time. Guaranteed to.

According to the fourth aspect of the present invention, the sensitivity of the engaging convex portion peripheral region as a check valve can be adjusted by providing a slit in the whole leaf spring to adjust (enhance) the flexibility of the engaging convex peripheral region. Therefore, the options for the leaf spring constituent material are expanded.

In addition, when a slit is provided only in a part of a leaf spring provided with a plurality of engaging projections, the peripheral region of the one engaging projection that is provided with a slit to enhance flexibility The peripheral edge region of the engagement convex portion, which functions as a valve and is not provided with a slit and has low flexibility, is always in close contact with the peripheral portion of the second oil supply hole, and the leaf spring is surrounded with respect to the second oil supply hole. Since it functions as positioning means for reliably positioning in the direction and the axial direction, proper opening / closing operation of the second oil supply hole by the check valve over a long period of time is more reliably ensured.

According to the fifth aspect, since the spherical body as the check valve is positioned in the circumferential direction and the axial direction with respect to the second oil supply hole, proper opening / closing operation of the second oil supply hole by the check valve over a long period is ensured. Is done.

It is sectional drawing of the valve operating mechanism of the OHC type internal combustion engine provided with the hydraulic lash adjuster which concerns on 1st Example of this invention. FIG. 3 is an enlarged perspective view of a check valve (plate spring) that is a main part of the hydraulic lash adjuster. FIG. 3 is a horizontal cross-sectional view (cross-sectional view taken along line III-III shown in FIG. 1) of the hydraulic lash adjuster at a second oil supply hole position equipped with a check valve (plate spring). It is a figure explaining the effect | action of a non-return valve (plate spring), (a) is sectional drawing which shows a mode that the non-return valve (plate spring) hold | maintains the state which closed the 2nd oil supply hole, (b) FIG. 5 is a cross-sectional view showing a state where a check valve (leaf spring) opens a second oil supply hole. It is sectional drawing of the valve operating mechanism of the OHC type | mold internal combustion engine provided with the hydraulic lash adjuster which concerns on 2nd Example of this invention. FIG. 3 is an enlarged perspective view of a check valve (plate spring) that is a main part of the hydraulic lash adjuster. FIG. 6 is a horizontal sectional view of the hydraulic lash adjuster at the second oil supply hole position equipped with a check valve (plate spring) (cross sectional view taken along line VII-VII shown in FIG. 5). FIG. 7 is an enlarged perspective view of a check valve (plate spring) that is a main part of a hydraulic lash adjuster for an internal combustion engine according to a third embodiment of the present invention. It is a horizontal sectional view (figure corresponding to Drawing 3) of a hydraulic lash adjuster in the 2nd oil supply hole position equipped with a check valve (plate spring). FIG. 9 is an enlarged perspective view of a check valve (leaf spring) that is a main part of a hydraulic lash adjuster for an internal combustion engine according to a fourth embodiment of the present invention. It is a horizontal sectional view (figure corresponding to Drawing 3) of a hydraulic lash adjuster in the 2nd oil supply hole position equipped with a check valve (plate spring). FIG. 9 is an enlarged perspective view of a check valve (plate spring) that is a main part of a hydraulic lash adjuster for an internal combustion engine according to a fifth embodiment of the present invention. It is a horizontal sectional view (figure corresponding to Drawing 3) of a hydraulic lash adjuster in the 2nd oil supply hole position equipped with a check valve (plate spring). It is an expanded longitudinal cross-sectional view in the 2nd oil supply hole position of a body. (A) is a perspective view of a check valve (plate spring), (a) is an enlarged perspective view of a check valve (plate spring) that is a main part of a hydraulic lash adjuster for an internal combustion engine according to a sixth embodiment of the present invention; b) is a perspective view of a leaf spring that backs up the check valve. It is an expanded longitudinal cross-sectional view in the 2nd oil supply hole position of a body. (A) is an enlarged vertical sectional view at the second oil supply hole position of the body, which is the main part of the hydraulic lash adjuster for an internal combustion engine according to the seventh embodiment of the present invention, and (b) is shown in (a). FIG. 6 is an enlarged longitudinal sectional view at a second oil supply hole position of a body that is a main part of a hydraulic lash adjuster for an internal combustion engine equipped with a modified example of a check valve. It is an expanded longitudinal cross-sectional view in the 2nd oil supply hole position of the body which is the principal part of the hydraulic lash adjuster for internal combustion engines which concerns on the 8th Example of this invention, (a) is a non-return valve (steel ball) 2nd. The figure which shows a mode that the oil supply hole of this is closed, (a) is a figure which shows a mode that a non-return valve (steel ball) opens the 2nd oil supply hole. It is sectional drawing of the valve operating mechanism of the OHC type internal combustion engine provided with the conventional hydraulic lash adjuster for internal combustion engines.

Hereinafter, embodiments of the present invention will be described based on examples.

1 to 4 show a first embodiment of a hydraulic lash adjuster for an internal combustion engine according to the present invention.

In these drawings, reference numeral 10 denotes a cylinder head. An air supply passage 12 provided in the cylinder head 10 opens into the combustion chamber A, and the opening is formed in the opening portion of the air supply passage 12 to the combustion chamber A. An operating valve element (intake valve) 14 to be opened and closed is inserted. The valve body 14 is biased by the valve body return spring 15 in the direction in which the air supply passage 12 is closed, and the upper end portion of the valve body 14 is in contact with a rocker arm 17 that swings as the cam 16 rotates. Reference numeral 16a is a cam nose.

Reference numeral 20 denotes a hydraulic lash adjuster provided adjacent to the valve body 14. The lash adjuster 20 has a structure in which a lash adjuster main body 22 is inserted into an adjuster mounting hole 30 provided in the cylinder head 10 that opens upward. The adjuster main body 22 includes a bottomed cylindrical body 24 that opens upward. The plunger 26 is inserted into the body 24 and slides in the vertical direction.

Oil supply holes (second oil supply holes) 24 b communicating with an oil gallery 32 that is an oil supply path provided in the cylinder head 10 are formed in the side wall of the body 24. Reference numeral 24 a denotes a lateral groove (a shallow groove having a shallow depth) provided in a region including the oil supply hole 24 b on the outer peripheral surface of the side wall of the body 24, even if the body 24 rotates in the circumferential direction with respect to the adjuster mounting hole 30. The communication between the oil supply hole 24b and the oil gallery 32 is ensured through the lateral groove (concave groove) 24a.

On the other hand, the plunger 26 which supports the end of the rocker arm 17 opposite to the contact portion with the valve body 14 from below and the swinging fulcrum of the rocker arm 17 is formed with a small hole 27b extending vertically in the lower center. It is composed of a cylindrical plunger lower portion 26B having an H-shaped longitudinal section and a cylindrical plunger upper portion 26A having a small hole 27c formed at the top and opening downward, both of which are welded and integrated coaxially. ing.

An oil supply hole (second oil supply hole) communicating with the oil supply hole (second oil supply hole) 24b on the body 24 side is formed on the side wall of the plunger upper portion 26A via an annular communication passage T formed between the plunger upper part 26A and the side wall of the body 24. 1 oil supply hole) 27a is formed, and the reservoir 28 in the plunger 26 is connected to the oil supply hole (first oil supply hole) 27a of the plunger 26, the annular communication passage T, and the oil supply hole (second second) of the body 24. The oil gallery 32 communicates with the oil supply hole 24b. Reference numeral 24c (see FIG. 4) denotes a lateral groove (a shallow groove having a shallow depth) provided in a region corresponding to the oil supply hole 24b on the inner peripheral surface of the side wall of the body 24, and reference numeral 27d (see FIG. 4) denotes a plunger 26. A lateral groove (a shallow groove having a shallow depth) provided in a region corresponding to the oil supply hole (second oil supply hole) 27a on the outer peripheral surface of the side wall of the plunger upper portion 26A. Even when the plunger 26 moves in the axial direction, it is formed in a position and a width that at least partially overlaps in the vertical direction, and the oil supply hole (first oil supply hole) 27a on the plunger 26 side and the oil supply hole (first line) on the body 24 side. (Annular communication hole T) 24b is formed.

That is, the plunger 26 and the body 24 are capable of relative rotation in the circumferential direction and relative sliding in the axial direction. Even if the positions of the both 26 and 24 are displaced in the circumferential direction or the axial direction, The communication between the oil supply hole (first oil supply hole) 27a of the plunger 26 and the oil supply hole (second oil supply hole) 24b of the body 24 is ensured via the communication passage T.

The reservoir 28 in the plunger 26 communicates with a high-pressure chamber 29 formed between the plunger 26 and the bottom of the body 24 through a small hole 27b below, and has a small hole 27c formed in the upper end of the plunger 26. Is open to the open air. The small hole 27c is for overflowing the oil in the reservoir 28 and supplying lubricating oil to the valve operating mechanism. Reference numeral 23 is a plunger spring, reference numeral 25a is a check ball that closes and holds the valve hole 27b by the urging force of the spring 25b, reference numeral 25c is a ball cage, and the check ball 25a that is a check valve is small by applying pressure to the hydraulic oil. The hole 27b is closed, and the plunger 26 is in a locked state to constitute a rocking fulcrum of the rocker arm 17. Reference numeral 24 d is a plunger retaining ring attached to the opening end of the body 24, and prevents the plunger 26 from departing from the body 24.

Reference numeral 40A denotes a check valve mounted in a lateral groove (concave groove) 24c formed on the outer peripheral surface of the side wall of the body 24, and holds the second oil supply hole 24b in a closed state when the operation of the internal combustion engine is stopped. In addition, the supply of the hydraulic oil into the reservoir 28 is stopped, and the second oil supply hole 24b is opened during operation of the internal combustion engine so that the hydraulic oil is supplied into the reservoir 28.

That is, the lateral groove (concave groove) 24c of the body 24 is held in a form in pressure contact with the bottom surface of the lateral groove (concave groove) 24c (the outer peripheral surface of the communication path T), and is pressurized from the oil gallery 32 to the second oil supply hole 24b. A check valve 40A constituted by a leaf spring 42 that operates (opens the second oil supply hole 24b) when the hydraulic oil is guided is loaded.

As shown in FIGS. 2 and 3, the check valve 40 </ b> A has an arc shape having a smaller curvature (larger curvature radius) than the circumference of the bottom surface of the lateral groove (concave groove) 24 c of the body 24 (the outer peripheral surface of the communication path T). An engagement convex portion 43 that bulges outward to be engageable with the second oil supply hole 24 b is formed at a substantially central portion in the longitudinal direction of the plate spring 42. Is provided.

The engagement protrusion 43 is formed by press-molding the leaf spring 42, and the outer periphery of the base end is formed in a spherical shape that matches the inner periphery of the second oil supply hole 24b, so that the second oil supply hole 24b is formed. As the peripheral region of the engaging convex portion 43 is further away from the peripheral portion of the second oil supply hole 24b, the opening surface property of the second oil supply hole 24b (the hydraulic oil flow passage cut-off) can be reliably blocked. Area) is increasing.

Further, the flexibility (spring coefficient) of the leaf spring 42 and the protruding length of the engaging protrusion 43 are set appropriately, and the second oil supply hole 24b of the check valve 40A is opened (the engaging protrusion of the leaf spring 42). When the peripheral region of the portion 43 is separated from the peripheral portion of the second oil supply hole 24b on the inner peripheral surface of the body 24, as shown in FIG. 4B, the distal end portion 43a of the engagement convex portion 43 is the second oil supply. It is configured not to drop out from the hole 24b. Thus, the engaging convex part 43 engaged with the second oil supply hole 24b is a positioning means for positioning the leaf spring 42 constituting the check valve 40A in the circumferential direction and the axial direction with respect to the second oil supply hole 24b. Configure.

That is, the protrusion length of the engagement convex portion 43 of the plate spring 42 is related to the oil supply hole 24b when the peripheral region of the engagement convex portion 43 of the plate spring 42 is separated from the peripheral portion of the oil supply hole 24b by the pressure of the hydraulic oil. The predetermined length is set so that the convex portion 43 does not deviate.

Further, the flexibility (spring coefficient) of the leaf spring 42 is adjusted, for example, by adjusting the material and section modulus of the leaf spring so that the peripheral region of the engaging convex portion 43 is separated from the peripheral portion of the oil supply hole 24b by the pressure of the hydraulic oil. In this case, the value is set to an appropriate value that does not hinder the sliding of the plunger 26 with respect to the body 24 by being displaced to the side groove (concave groove) 27d side on the plunger 26 side.

Further, in order to assemble the check valve 40A (plate spring 42) into the lateral groove (concave groove) 24c of the body 24, the diameter of the plate spring 42 is reduced, and the engagement convex portion 43 is lubricated as shown by phantom lines in FIG. When the check valve 40A is loaded in the lateral groove (concave groove) 24c of the body 24 so as to coincide with the hole 24b, the check valve 40A is caused by the elastic force of the leaf spring 42 as shown in FIG. It is self-held in a form in which it is pressed (contacted) to the bottom of the lateral groove (concave groove) 24c.

During the operation of the internal combustion engine, the pressurized hydraulic oil introduced from the oil gallery 32 to the second oil supply hole 24b is engaged with the check valve 40A (the engagement protrusion of the leaf spring 42) engaged with the oil supply hole 24b. 4 (b), the engagement protrusion 43 peripheral area of the leaf spring 42 is elastically deformed inward in the radial direction. For this reason, when the internal combustion engine is stopped, the peripheral region of the engagement convex portion 43 of the leaf spring 42 that is in close contact with the bottom surface (the peripheral portion of the second oil supply hole 24b) of the lateral groove (concave groove) 24c is the peripheral edge of the second oil supply hole 24b. As shown by the arrow in FIG. 4B, the pressurized hydraulic fluid flows into the annular communication passage T from the gap formed between the peripheral region of the leaf spring 42 and the peripheral portion of the oil supply hole 24b. The hydraulic oil is supplied to the reservoir 28 through the first oil supply hole 27a. When the operation of the internal combustion engine is stopped, the pressing force to the check valve 40A (the peripheral region of the engagement convex portion 43 of the leaf spring 42) by the pressurized hydraulic fluid disappears, and the engagement is performed by the elastic force of the leaf spring 42. The form in which the peripheral area of the convex portion 43 returns to the original position where it engages with the second oil supply hole 24b, and the peripheral area of the engagement convex portion 43 of the leaf spring 42 closes the second oil supply hole 24b (see FIG. 4A). ) And hydraulic oil is not supplied to the reservoir 28.

In the present embodiment, as described above, the check valve 40A (plate spring 42) is provided on the engagement convex portion 43 of the plate spring 42 that engages with the second oil supply hole 24b with respect to the second oil supply hole 24b. Is provided in the circumferential direction and the axial direction, so that the opening / closing operation of the second oil supply hole 24b by the check valve 40A is ensured for a long period of time.

During the operation of the internal combustion engine, the hydraulic oil in the high pressure chamber returns to the reservoir 28 via the gap between the body 24 and the plunger 26 and the first oil supply hole 27a, and the recycle action of leak down oil is performed. When the operation is stopped, the second oil supply hole 24b is held in a closed state by the check valve 40A, and the oil level H of the reservoir 28 communicating with the high pressure chamber 29 is changed to the level of the body 24 as shown in FIG. Since it does not drop below the open end level and a large amount of hydraulic oil is retained in the reservoir 28, there is no possibility that air will be sucked into the high-pressure chamber 29 when the internal combustion engine is restarted.

5 to 7 show a hydraulic lash adjuster according to a second embodiment of the present invention.

In the second embodiment, the second oil supply hole 24b is provided at two circumferentially equally divided portions on the side wall of the body 24, and the check valve 40B loaded in the lateral groove (concave groove) 24c on the side wall of the body 24 is provided. The plate spring 42 that constitutes is provided with engagement convex portions 43 that can be engaged with the second oil supply hole 24b at two locations in the longitudinal direction.

During operation of the internal combustion engine, the hydraulic oil in the oil gallery 32 is guided to the pair of second oil supply holes 24b via the lateral grooves 24a provided on the outer periphery of the side wall of the body 24, and the hydraulic oil introduced into the oil supply holes 24b is added. Due to the pressure, the check valve 40B (the peripheral region of the pair of engaging protrusions 43 of the leaf spring 42) engaged with the oil supply hole 24b is elastically deformed radially inward almost simultaneously, so that the two oil supply holes 24b are substantially Open at the same time. For this reason, since the pressurized hydraulic oil is guided into the annular communication path T from each of the two second oil supply holes 24b, the pressurized hydraulic oil is smoothly supplied to the reservoir 28 accordingly.

In addition, the engagement convex portions 43 of the leaf springs 42 respectively engaged with the second oil supply holes 24b provided at approximately two equally divided positions in the circumferential direction of the body 21 respectively connect the plate springs 42 to the second oil supply holes 24b. Since the check valve 40B in the present embodiment has a function of positioning in the circumferential direction and the axial direction, the check valve 40B in the present embodiment is more circumferential in relation to the second oil supply hole 24b than the check valve 40A in the first embodiment described above. Excellent positioning function in the axial direction.

Others are the same as those in the first embodiment, and the description thereof is omitted by giving the same reference numerals.

8 and 9 show a hydraulic lash adjuster for an internal combustion engine according to a third embodiment of the present invention.

In the third embodiment, a slit 42a extending in the longitudinal direction of the leaf spring is provided in a region excluding both longitudinal ends of the leaf spring 42 constituting the check valve 40C and the peripheral region of the engaging convex portion 43. When the check valve 40C opens the oil supply hole 24b, the pressurized hydraulic oil can flow into the annular communication passage T through the slit 42a, and the opening / closing operation of the oil supply hole 24b by the check valve 40C is quicker. It becomes.

That is, during the operation of the internal combustion engine, the peripheral area of the engagement convex portion 43 of the leaf spring 42 is separated from the peripheral portion of the oil supply hole 24b by the pressure of the pressurized hydraulic fluid guided to the oil supply hole 24b (see FIG. 4B). The pressurized hydraulic fluid that has flowed into the lateral groove (concave groove) 24c from the formed gap wraps around the communication path T from the side edge of the leaf spring 42, and also enters the communication path T from the slit 42a of the leaf spring 42. Inflow.

Further, the section modulus of the leaf spring 42 is reduced by providing the slit 42a, and the flexibility (spring modulus) of the leaf spring 42 is increased accordingly, but the longitudinal direction of the leaf spring 42 constituting the check valve 40C is almost the same. The slit 42a extends throughout, and the flexibility (spring coefficient) of the peripheral areas of the two engaging projections 43 is similarly increased, and the check valve 40B of the second embodiment described above (FIG. 6). The sensitivity is higher than that of (see). That is, the check valve 40C (the area around the engaging projection 43) starts elastic deformation at a pressure lower than that of the check valve 40B and has a large amount of elastic deformation. The supply of hydraulic oil into the 28 is also quick.

Others are the same as those in the second embodiment, and the description thereof is omitted by giving the same reference numerals.

10 and 11 show a hydraulic lash adjuster for an internal combustion engine according to a fourth embodiment of the present invention.

In the third embodiment described above, the slit 42a is provided in almost the entire longitudinal direction of the leaf spring 42 that constitutes the check valve 40C, so that the flexibility (spring coefficient) of the leaf spring 42 as a whole, that is, two engagements. Although the flexibility (spring coefficient) of the peripheral region of the joint convex portion 43 was similarly increased, in this fourth embodiment, only the region of approximately half the longitudinal direction of the leaf spring 42 constituting the check valve 40D. Is provided with a slit 42a, and the flexibility (spring coefficient) of only the peripheral region of the engaging convex portion 43-1 in the region where the slit 42a is provided is enhanced.

For this reason, the engagement convex portion 43-1 peripheral region with increased flexibility (spring coefficient) is elastically deformed in accordance with the pressure of the hydraulic oil guided to the second oil supply hole 24b, and the second In contrast to the function of a check valve that opens and closes the oil supply hole 24b, the peripheral area of the engaging convex portion 43-2, which is not provided with the slit 42a and has low flexibility, receives pressurized hydraulic oil in the second oil supply hole 24b. Even when guided, the second oil supply hole 24b is held in a closed state without elastic deformation. In other words, the peripheral edge of the engaging protrusion 43-2 in the region where the slit 42a is not provided is always held in close contact with the peripheral edge of the second oil supply hole 24b regardless of whether the internal combustion engine is operating or stopped. The engaging convex portion 43-2 functions as a positioning means for reliably positioning the leaf spring 42 in the circumferential direction and the axial direction with respect to the second oil supply hole 24b.

Therefore, the circumferential direction and axial positioning function of the check valve 40D is superior to the circumferential direction and axial positioning function of the check valve 40C in the third embodiment.

Others are the same as those of the third embodiment, and the description thereof is omitted by giving the same reference numerals.

12 to 14 show a hydraulic lash adjuster for an internal combustion engine according to a fifth embodiment of the present invention.

In the fifth embodiment, as in the case of the

check valves

40B, 40C, 40D in the second to fourth embodiments described above, the leaf spring 42 constituting the check valve 40E has two oil supply holes. Engaging projections 43 are provided to engage with 24b respectively, and the longitudinal end portions of the leaf spring 42 and the peripheral region of the engaging projection 43 are formed in the same manner as in the case of the check valve 40C in the third embodiment. In the excluded area, a slit 42a extending in the longitudinal direction is provided, and the flexibility of the peripheral area of the engaging protrusion 43 is enhanced.

Further, the check valve 40E is configured such that the leaf spring 42 is wound in a coil shape and loaded in the lateral groove (concave groove) 24c, and a part of the leaf spring 42 is overlapped in the radial direction as shown in FIG. Has been.

For this reason, the peripheral area of the engagement convex portion 43 of the leaf spring 42 is elastically deformed radially inward by the pressure of the hydraulic oil, but the periphery of the engagement convex portion 43 is partly formed by a part of the leaf spring 42 extending inward. The deformation of the region inward in the radial direction is suppressed, and the peripheral region of the engagement convex portion 43 of the leaf spring 42 is not deformed beyond the depth of the lateral groove (concave groove) 24c. A part of the stop valve 40E (leaf spring 42) does not move to the lateral groove (concave groove) 27d on the plunger 26 side and does not prevent the plunger 26 from sliding.

15 and 16 show a hydraulic lash adjuster for an internal combustion engine according to a sixth embodiment of the present invention.

In the sixth embodiment, as shown in FIG. 15 (a), the check valve 40F has the same structure as the check valve 40C (see FIG. 8 (a)) in the third embodiment. A leaf spring-like backup member 42f (see FIG. 15B) is disposed so as to cover the entire check valve 40F, and is configured to suppress elastic deformation of the check valve 40F inward in the radial direction. Yes.

The backup member 42f is constituted by a leaf spring having a width larger than that of the leaf spring 42 constituting the check valve 40F, and a leg that can be pressed against the bottom surface of the lateral groove (concave groove) 24c at both side edges in the width direction. A portion 42f1 is formed to increase the rigidity of the backup member 42f.

Further, in the state where the check valve 40F (leaf spring 42) and the backup member 42f are loaded in the lateral groove (concave groove) 24c, the height t1 from the bottom surface of the lateral groove (concave groove) 24c of the backup member 42f is the lateral groove (concave groove). ) Between the plate spring 42 constituting the check valve 40F and the backup member 42f covering the check valve 40F (plate spring 42), the hydraulic oil pressure is applied between the plate spring 42 and the check valve 40F (plate spring 42). When the peripheral region of the joint convex portion 43 is elastically deformed and separated from the peripheral portion of the oil supply hole 24b, a gap t3 is formed that is sufficient to sufficiently open the oil supply hole 24b.

FIG. 17 (a) shows a main part of a hydraulic lash adjuster for an internal combustion engine according to a seventh embodiment of the present invention.

In the first to sixth embodiments described above, the lateral groove (concave groove) 24c provided on the inner peripheral surface of the side wall of the body 24 and the lateral groove (concave groove) 27d provided on the outer peripheral surface of the side wall of the plunger 26 are used. An annular communication passage T is formed to connect the oil supply hole (first oil supply hole) 27a on the plunger 26 side and the oil supply hole (second oil supply hole) 24b on the body 24 side. In this embodiment, the lateral groove (concave groove) 27d is not formed on the outer peripheral surface of the side wall of the plunger 26, and only the lateral groove (concave groove) 24c formed on the inner peripheral surface of the side wall of the body 24 is used to supply oil on the plunger 26 side. An annular communication path T is configured to connect the hole 27a and the oil supply hole 24b on the body 24 side.

A lateral groove (concave groove) 24c formed on the side wall of the body 24 is loaded with a check valve 40A (a leaf spring 42 provided with an engaging convex portion 43) employed in the first embodiment. ing.

Other configurations are the same as those of the first embodiment, and the description thereof is omitted by attaching the same reference numerals.

In this embodiment, since the lateral groove (concave groove) 27d is not formed on the side wall of the plunger 26, the peripheral region of the engaging convex portion 43 is greatly elasticized by the pressurizing force of the hydraulic oil guided to the oil supply hole 24b on the body 24 side. Even if it is deformed, the problem of interference with the lateral groove (concave groove) 27d provided around the side wall outer peripheral surface of the plunger 26, which is a concern in the case of the first to sixth embodiments described above, does not occur.

In the first to seventh embodiments described above, the engaging projection 43 provided on the leaf spring 42 is formed in a spherical shape, but the engaging projection 43 is as shown in FIG. In addition, the base end portion side may be formed in a tapered cylindrical shape (conical truncated cone shape) having an outer diameter aligned with the second oil supply hole 24b.

When the engagement convex portion 43 has a tapered cylindrical shape (conical truncated cone shape), the opening area (operation) of the second oil supply hole 24b with respect to the distance from the peripheral portion of the second oil supply hole 24b in the peripheral region of the engagement convex portion 43 The ratio of the increase in the oil flow passage cross-sectional area) is larger than that in the case where the engagement convex portion 43 is spherical, and the inflow of hydraulic oil into the annular communication passage T from the second oil supply hole 24b accordingly. Becomes smooth.

FIG. 18 shows a main part of a hydraulic lash adjuster for an internal combustion engine according to an eighth embodiment of the present invention.

The eighth embodiment is different from the first embodiment in the structure of the check valve 40G and the means for positioning the check valve 40G in the circumferential direction with respect to the body 24. The structure is the same as that shown in the first embodiment, and a duplicate description thereof will be omitted.

That is, in the first to sixth embodiments described above, the lateral groove (concave groove) 24c provided on the inner peripheral surface of the side wall of the body 24 and the lateral groove (concave groove) provided on the outer peripheral surface of the side wall of the plunger 26 are provided. 27d constitutes an annular communication passage T that communicates the oil supply hole (first oil supply hole) 27a on the plunger 26 side and the oil supply hole (second oil supply hole) 24b on the body 24 side. In this embodiment, an annular communication passage T is constituted by a lateral groove (concave groove) 24c formed on the side wall of the body 24. In this eighth embodiment, however, the peripheral surface of the side wall of the plunger 26 is provided on the outer peripheral surface. An annular communication path T is constituted only by the lateral grooves (concave grooves) 27d.

In the first to seventh embodiments, the check valves 40A to 40F are made of metal or resin leaf springs. In the eighth embodiment, the check valve 40G is A steel ball 50 having a specific gravity greater than that of the hydraulic oil, in which a part of the outer peripheral surface engages with an oil supply hole 24 b provided in the side wall of the body 24.

Further, a longitudinal groove 24d extending upward from the oil supply hole 24b and allowing the steel ball 50F to move in the vertical direction is provided on the inner peripheral surface of the side wall of the body 24, and the check valve 40G (steel ball 50) and the oil supply are provided. The holes 24b are positioned in the circumferential direction.

During the operation of the internal combustion engine, the check valve 40G (steel ball 50) whose outer peripheral surface is engaged with the oil supply hole 24b by the pressurized hydraulic fluid guided from the oil gallery 32 to the oil supply hole 24b is: It is pressed in a direction deviating from the oil supply hole 24b, and rolls (moves) upward along the vertical groove 24 to open the oil supply hole 24b. Then, the pressurized hydraulic fluid flows into the annular communication passage T from the opened oil supply hole 24b. On the other hand, when the operation of the internal combustion engine is stopped, the upward pressing force acting on the check valve 40G (steel ball 50) by the pressurized hydraulic fluid disappears, and the check valve 40G (steel ball 50) has its own weight and the vertical groove. It rolls downward (moves) along 24d, and a part thereof returns to the original position where it engages with the oil supply hole 24b, and the oil supply hole 24b is closed.

When the steel ball 50 is engaged with the oil supply hole 24b at the position of the stepped portion 24b1 provided in the oil supply hole 24b, and the pressure of the hydraulic oil is applied, the vertical groove 24d is provided. By being restrained only by the movement along the circumferential direction, it is positioned in the circumferential direction and the axial direction with respect to the oil supply hole 24b. Guaranteed.

Further, the check valve 40G is composed of one steel ball 50, and the circumferential and axial positioning means composed of the vertical grooves 24d are also simple, so that the lash adjuster incorporating the check valve 40G can be used. The structure is also very simple.

In the eighth embodiment, the check valve 40G is constituted by one steel ball 50. For example, the steel ball 50 is accommodated in each of the longitudinal grooves 24d formed at a plurality of locations in the circumferential direction. It may be a structure. In such a configuration, the plurality of steel balls 50 simultaneously open and close the oil supply holes 24b during operation / stop of the internal combustion engine, so that the supply of hydraulic oil to the reservoir 28 is smooth.

In a valve mechanism of an internal combustion engine such as an automobile, the valve gap changes during operation under the influence of wear or thermal expansion. Therefore, a hydraulic lash adjuster is known as a device for appropriately correcting this gap. The hydraulic lash adjuster of the present invention is mainly used by being incorporated in a valve operating device of an internal combustion engine such as an automobile.

DESCRIPTION OF SYMBOLS 10 Cylinder head 17 Rocker arm 20 Hydraulic lash adjuster 22 Rush adjuster main body 23 Press spring 24 Body 24b Cylinder 24b Oil supply hole (2nd oil supply hole) drilled in side wall of body
T annular communication passage 24c transverse groove (concave groove) constituting the annular communication passage
24d Vertical groove which is a positioning means for positioning the steel ball in the circumferential direction with respect to the oil supply hole 25a Check ball which is a check valve 26 Plunger 26A Plunger upper part 26B Plunger lower part 27a Oil supply hole (first oil supply hole drilled in the side wall of the plunger Hole)
27b Valve hole 27d Transverse groove (concave groove) constituting an annular communication path
28 Reservoir 29 High pressure chamber (hydraulic chamber)
30 Rush adjuster mounting hole 32

Oil gallery

40A, 40B, 40C, 40D, 40E, 40F, 40G Check valve 42 Plate spring constituting check valve 43 Engagement convex part engaging with oil supply hole 50 A steel ball, which is a sphere constituting a check valve

Claims

A body that is a cylinder with a bottom that opens upward, and a plunger that slides on the inner peripheral surface of the body to define a high-pressure chamber at the bottom and has an upper end as an operating end. There are provided a reservoir that communicates with an external lubrication passage through a first lubrication hole drilled in the second wall and a second lubrication hole drilled in the side wall of the body, and a valve hole that communicates the reservoir with the high-pressure chamber. And a hydraulic pressure lash adjuster for an internal combustion engine in which a check valve for opening / closing the valve hole according to pressure reduction / pressure increase of the high pressure chamber and a pressure spring for biasing the plunger in the extending direction are accommodated in the high pressure chamber In
The first oil supply hole and the second oil supply hole communicate with each other via an annular communication path provided between a side wall of the plunger and a side wall of the body, and the first oil supply hole and the second oil supply hole are formed in the annular communication path. A check valve that opens and closes the second oil supply hole is provided at a position corresponding to the second oil supply hole in association with the pressure of the hydraulic oil introduced from the external oil supply passage to the second oil supply hole. A hydraulic lash adjuster for an internal combustion engine.
The annular communication path is configured by a lateral groove provided on the inner peripheral surface of the side wall of the body, and the check valve is configured by a belt-like leaf spring that is self-held so as to be in pressure contact with the bottom surface of the lateral groove. The leaf spring is provided with an engaging projection for engaging the second oil supply hole to position the leaf spring at a predetermined position in the circumferential direction and the axial direction. The hydraulic lash adjuster for internal combustion engines as described.
The second oil supply holes are provided at a plurality of substantially equal positions in the circumferential direction of the side wall of the body, and the engagement springs are provided on the leaf springs to engage with the plurality of second oil supply holes, respectively. The hydraulic lash adjuster for an internal combustion engine according to claim 2, wherein the hydraulic lash adjuster is used.
4. The hydraulic lash adjuster for an internal combustion engine according to claim 3, wherein the leaf spring is provided with a slit to adjust flexibility (spring coefficient) of a region including the engagement convex portion. .
The annular communication path is configured by a lateral groove provided around the outer peripheral surface of the side wall of the plunger, and the check valve is movable along the lateral groove, and the second oil supply hole is provided with a portion of the outer peripheral surface thereof. It is composed of a sphere with a greater specific gravity than the hydraulic oil with which the part engages, and on the inner peripheral surface of the side wall of the body, the sphere is allowed to move in the vertical direction by extending upward from the second oil supply hole 2. The hydraulic lash adjuster for an internal combustion engine according to claim 1, wherein a vertical groove is provided, and the spherical body is positioned in a circumferential direction and an axial direction with respect to the second oil supply hole.